The European Union Emissions Trading Scheme is designed to reduce greenhouse gas emissions. It provides an economic incentive to reduce emissions in the most cost-effective way by capping greenhouse gas emissions from approximately 11,000 energy intensive installations in power generation and manufacturing industry sectors in the 28 EU countries plus Iceland, Liechtenstein and Norway - The Europe Economic Area (EEA). It also covers flights to, from, between and within the EEA Member States to varying degrees. The Scheme Regulates 45% of emissions in EU and is Currently in Phase 3 (2013-2020). Airlines/aircraft can use simplified procedures if they are classed as a small emitters (<25,000 tonnes in total to from and within the EEA, or <3,000 tonnes within EEA.)
ICAO’s Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA), is an offsetting compliance regime aimed at achieving carbon neutral growth (CNG) from 2020 onward. Airlines are monitoring for the baseline at present with the CORSIA pilot phase beginning in 2021 where airlines will have to offset emissions above 2020 levels to achieve CNG.
Details of the eligible offsets and how this information will be published a re still being decided upon by ICAO.
There are also regional schemes including aviation emissions, both planned and already in place, in South Korea, Mexico, New Zealand and China.